Bioinformatics analysis of miRNA and mRNA expression profiles to reveal the key miRNAs and genes in osteoarthritis

Background Osteoarthritis (OA) is a chronic degenerative joint disease and the most frequent type of arthritis. This study aimed to identify the key miRNAs and genes associated with OA progression. Methods The GSE105027 (microRNA [miRNA/miR] expression profile; 12 OA samples and 12 normal samples) and GSE48556 (messenger RNA [mRNA] expression profile; 106 OA samples and 33 normal samples) datasets were selected from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) and miRNAs (DEMs) were analyzed using the limma and ROCR packages in R, respectively. The target genes that negatively correlated with the DEMs were predicted, followed by functional enrichment analysis and construction of the miRNA-gene and miRNA-transcription factor (TF)-gene regulatory networks. Additionally, key miRNAs and genes were screened, and their expression levels were verified by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). Results A total of 1696 DEGs (739 upregulated and 957 downregulated) and 108 DEMs (56 upregulated and 52 downregulated) were identified in the OA samples. Furthermore, 56 target genes that negatively correlated with the DEMs were predicted and found to be enriched in three functional terms (e.g., positive regulation of intracellular protein transport) and three pathways (e.g., human cytomegalovirus infection). In addition, three key miRNAs ( miR-98-5p , miR-7-5p , and miR-182-5p ) and six key genes (murine double minute 2, MDM2 ; glycogen synthase kinase 3-beta, GSK3B ; transmembrane P24-trafficking protein 10, TMED10 ; DDB1 and CUL4-associated factor 12, DCAF12 ; caspase 3, CASP3 ; and ring finger protein 44, RNF44 ) were screened, among which the miR-7-5p → TMED10/DCAF12 , miR-98-5p → CASP3/RNF44 , and miR-182-5p → GSK3B pairs were observed in the regulatory network. Moreover, the expression levels of TMED10 , miR-7-5p , CASP3 , miR-98-5p , GSK3B , and miR-182-5p showed a negative correlation with qRT-PCR verification. Conclusion MiR-98-5p , miR-7-5p , miR-182-5p , MDM2 , GSK3B , TMED10 , DCAF12 , CASP3 , and RNF44 may play critical roles in OA progression.